 |
 |
 |
|
Alternative Names: Adenomas.
Although pituitary tumors are classified as brain tumors they have very few similarities to other types of brain tumor. Much general information about brain tumors will not be appropriate for people with pituitary tumors, although you may still wish to read it.
The pituitary gland is a small oval-shaped gland found at the base of the brain, below the optic nerve (the nerve which leads to and from the eye). The pituitary gland produces hormones which control and regulate the other glands in the body. These glands release hormones that are responsible for the body's growth and metabolism. The pituitary gland is divided into two parts: the anterior (front) and posterior (back).
Cells within the brain normally grow in an orderly and controlled way, but if for some reason this order is disrupted, the cells continue to divide and form a lump or tumor. A tumor may be either benign or malignant. Although a benign tumor can continue to grow, the cells do not spread from the original site. In a malignant tumor, the cells can invade and destroy surrounding tissue and may spread to other parts of the brain.
Incidence; Causes & Development
Pituitary tumors are one of the most common types and make up nearly 10% of all brain tumors. They are most commonly found in young or middle-aged adults.
As with most brain tumors, the cause of pituitary tumors is unknown. Research is being carried out into possible causes.
Signs & Symptoms
Signs and symptoms of pituitary tumors are caused either by direct pressure from the tumor itself, or by a change in the normal hormone levels. As the tumor grows, it puts pressure on the optic nerve (which leads to the eye) and this often causes headaches and vision problems.
Symptoms caused by a change in hormone levels usually take a long time to develop.
Prolactin-secreting tumors are the most common type of secreting tumor. Women with this type of tumor may notice that their monthly periods stop and they may also produce small amounts of breast milk. Symptoms in men may include impotence (loss of the ability to have an erection).
Infertility (inability to have children) is common in both men and women and the tumor may be discovered during routine tests for infertility.
Symptoms of other secreting tumors will relate to the hormones that are released.
Growth hormone-secreting tumors: Excess production of growth hormones can cause a condition called giantism. This leads to abnormal growth that is known as acromegaly. This causes enlargement of the hands, feet, lower jaw and brows, and can also lead to high blood pressure and diabetes.
TSH-secreting tumors: A tumor that releases too much TSH causes a disruption in the body's normal metabolism. However, these tumors are extremely rare.
ACTH-secreting tumors: Over-production of ACTH can produce a number of symptoms, including Cushing's syndrome, which is characterised by a round face (known as moon-face), weight gain, increased facial hair in women, and mental changes such as depression.
Other anterior pituitary tumors: Tumors that secrete FSH or LH are very rare and are likely to cause infertility.
Posterior pituitary tumors: Tumors in the posterior pituitary are very rare and disturbances in this area are more likely to be caused by pressure being applied to the area from the surrounding tissues.
The most common symptom of a problem in the posterior pituitary is a condition called diabetes insipidus (not the same as the more common diabetes mellitus). The main symptom of diabetes insipidus is being very thirsty and passing large amounts of very weak urine.
Some problems which seem to be other diseases may in fact be a tumor. For example, a pituitary tumor can present like a subarachnoid hemorrhage, which is a kind of stroke.
Diagnosis & Tests
Pituitary tumors are either secreting (producing hormones) or non-secreting tumors (not producing hormones). Secreting tumors can release excess amounts of any of the pituitary hormones, and are named after the hormone that is being over-produced, for example, a prolactin-secreting tumor.
Pituitary tumors are often discovered during a blood test. If high levels of pituitary hormones are found in your blood, your doctor may arrange for you to have a CT scan or MRI scan. The scans will normally be able to confirm whether a pituitary tumor is present or not.
CT (computerised tomography) scan: A CT scan takes a series of X-rays which build up a three-dimensional picture of the inside of the body. The scan is painless but takes from 10-30 minutes. CT scans use a small amount of radiation, which will be very unlikely to harm you and will not harm anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.
Most people who have a CT scan are given a drink or injection to allow particular areas to be seen more clearly. This may make you feel hot all over. Before having the injection or drink, it is important to tell the person doing this test if you are allergic to iodine or have asthma.
MRI (magnetic resonance imaging) scan: This test is similar to a CT scan, but uses magnetism instead of X-rays to build up a detailed picture of areas of your body. During the scan you will be asked to lie very still on the couch inside a long tube for about 30 minutes. It is painless but can be uncomfortable, and some people feel a bit claustrophobic during the scan. It is also noisy, but you will be given earplugs or headphones.
Some people are given an injection of dye into a vein in the arm, but this usually does not cause any discomfort.
Eye tests: By examining your eyes, your doctor can detect pressure on the optic nerve, which may indicate that a tumor is present. A simple test may also be done to check your visual fields (range of vision).
Treatment & Prevention
In order to plan treatment, it is important to find out as much as possible about the type, position and size of the tumor. This is done through a number of tests and investigations.
Your treatment will usually be planned by a team of specialists known as a multidisciplinary team (MDT). The team will usually include a doctor who operates on the brain (neurosurgeon), a doctor who specialises in treating illnesses of the brain (neurologist), a specialist nurse and possibly other health professionals, such as a physiotherapist or a dietitian.
Surgery is the most common treatment for most pituitary tumors. The aim of surgery is to remove the tumor and leave at least some of the normal pituitary gland behind. This is not always possible, and in some cases the whole gland needs to be removed.
Surgery is usually carried out by making a small cut on the inside of the roof of the nose, or by making a small opening under the upper lip, to be able to reach the pituitary gland. This makes recovery after surgery much quicker than other operations for brain tumous. Your doctor will explain the operation to you in more detail beforehand.
Drug treatment. Some prolactin-secreting tumors can be treated with a drug called bromocriptine, which reduces the production of prolactin.
If the whole pituitary gland is removed, drugs will have to be taken to replace the hormones that are normally produced (hormone replacement).
Radiotherapy treatment uses high-energy rays to destroy abnormal cells, and is an extremely effective and safe form of treatment, which is often used following pituitary surgery for all types of tumor.
Prognosis
Almost all tumors of the pituitary gland are benign and do not spread.
|
|
 |
|
 |
Signs, symptoms & indicators of Pituitary Tumor:
KEY | | Weak or unproven link |
GLOSSARY
Anterior
In the front or forward part of the organ or toward the head of the body.
Asthma (Asthmatic)
A lung disorder marked by attacks of breathing difficulty, wheezing, coughing, and thick mucus coming from the lungs. The episodes may be triggered by breathing foreign substances (allergens) or pollutants, infection, vigorous exercise, or emotional stress. Extrinsic Asthma is triggered by pollen, chemicals or some other external agent; Intrinsic Asthma is triggered by boggy membranes, congested tissues, or other native causes… even adrenalin stress or exertion.
Benign
Literally: innocent; not malignant. Often used to refer to cells that are not cancerous; they tend to grow slowly and don't spread (metastasize) like cancer tumors do.
Computerised Tomography (CAT Scan, Computed Tomography, Computerized Axial Tomography, CT Scan)
A scanning procedure using X-rays and a computer to detect abnormalities of the body's organs. This technique provides cross-sectional images of body organs, which is much clearer than those provided by conventional X-rays.
Diabetes Insipidus
Excessive production of urine, usually due to insufficient production of antidiuretic hormone.
Diabetes Mellitus (Diabetes, Diabetic, Diabetics)
A disease with increased blood glucose levels due to lack or ineffectiveness of insulin. Diabetes is found in two forms; insulin-dependent diabetes (juvenile-onset) and non-insulin-dependent (adult-onset). Symptoms include increased thirst; increased urination; weight loss in spite of increased appetite; fatigue; nausea; vomiting; frequent infections including bladder, vaginal, and skin; blurred vision; impotence in men; bad breath; cessation of menses; diminished skin fullness. Other symptoms include bleeding gums; ear noise/buzzing; diarrhea; depression; confusion.
Gland (Glands)
The glandular system is one of the most important and complicated systems of the body. Gland tissue can be either an organ or general tissue that secretes chemicals and there are two types of gland: exocrine and endocrine. Those glands which secrete chemicals through tubules or ducts are called exocrine and include sweat, tear and salivary glands. Ductless glands - part of the endocrine system - secrete special chemicals (hormones) directly into the blood.
Hemorrhage (Hemorrhaging)
Profuse blood flow.
Hormones (Hormone)
Chemical substances secreted by a variety of body organs that are carried by the bloodstream and usually influence cells some distance from the source of production. Hormones signal certain enzymes to perform their functions and, in this way, regulate such body functions as blood sugar levels, insulin levels, the menstrual cycle, and growth. These can be prescription, over-the-counter, synthetic or natural agents. Examples include adrenal hormones such as corticosteroids and aldosterone; glucagon, growth hormone, insulin, testosterone, estrogens, progestins, progesterone, DHEA, melatonin, and thyroid hormones such as thyroxine and calcitonin.
Iodine
A essential mineral that is an integral part of the thyroid hormones, thyroxin and triiodothyronine which have important metabolic roles and govern basal metabolism. The best known iodine deficiency symptom is goiter. Other iodine deficiency problems are reduced vitality, hypothyroidism, inability to think clearly, low resistance to infection, loss of control of the muscles of the mouth resulting in mouth contortion and drooling, defective teeth, tendency to obesity and cretinism which is a congenital abnormal condition marked by physical stunting and mental deficiency.
Magnetic Resonance Imaging (MRI)
A technique used in diagnosis that combines radio waves and magnetic forces to produce detailed images of the internal structures of the body.
Malignant (Cancerous)
Dangerous. Mainly used to describe a cancerous growth -- when used this way, it means the growth is cancerous and predisposed to spreading.
Metabolism (Metabolic, Metabolize, Metabolizes, Metabolizing)
The chemical processes of living cells in which energy is produced in order to replace and repair tissues and maintain a healthy body. Responsible for the production of energy, biosynthesis of important substances, and degradation of various compounds. Also defined as the sum total of changes in an organism in order to achieve a balance (homeostasis): Catabolic burns up, anabolic stores and builds up; the sum of their work is metabolism.
Pituitary (Pituitary Gland)
The pituitary gland is a small (half-inch), bean-shaped organ that hangs down from the lower center of the brain on a stalk attached to another gland, the hypothalamus. Weighing less than one gram, the pituitary gland is often called the "master gland" since it controls the secretion of hormones by other endocrine glands. It regulates many body activities, and is partitioned into front and back lobes. The front lobe is stimulated by the hypothalamus, and produces any one of six different hormones that in turn stimulate the thyroid, adrenal and reproductive glands, and also breast milk production.
Prolactin
An anterior pituitary peptide hormone that initiates and maintains lactation.
Radiation Therapy (Radiotherapy)
The use of high-energy rays to kill cancer cells. Depending on the stage of the disease, treatment with radiation may be given alone or with chemotherapy. Radiation therapy is local therapy; it affects cancer cells only in the treated area. External radiation does not cause the body to become radioactive. Most often, treatment is given on an outpatient basis in a hospital or clinic.
Stroke (Stroke-Type Event)
A sudden loss of brain function caused by a blockage or rupture of a blood vessel that supplies the brain, characterized by loss of muscular control, complete or partial loss of sensation or consciousness, dizziness, slurred speech, or other symptoms that vary with the extent and severity of the damage to the brain. The most common manifestation is some degree of paralysis, but small strokes may occur without symptoms. Usually caused by arteriosclerosis, it often results in brain damage.
Syndrome
A medical condition characterized by a collection of related symptoms (what the patient feels) and signs (what a doctor can observe or measure).
Tumor (Tumors, Tumour, Tumours)
An abnormal growth of tissue resulting from uncontrolled, progressive multiplication of cells and serving no physiological function; a neoplasm. Literally, a swelling; in the past the term has been used in reference to any swelling of the body, no matter what the cause. However, the word is now being used almost exclusively to refer to a neoplastic mass, and the more general usage is being discarded.
X-rays (X-ray)
High-energy radiation used to take pictures of areas inside the body.
Last updated: Apr 13, 2008
|
 |
|
|
